Process for the oligomerization of ethylene in methanol

ABSTRACT

Ethylene is oligomerized by reacting ethylene in methanol under oligomerization conditions in contact with a nickel ylide defined by the following Formula I: ##STR1## wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7  and R 8  are either alike or different members selected from the group consisting of hydrogen, alkyl radicals having from about one to about 24 carbon atoms, preferably from about one to about 10 carbon atoms; aryl radicals having from about six to about 20 carbon atoms, preferably from about six to about 10 carbon atoms; alkenyl radicals having from about two to about 30 carbon atoms, preferably from about two to about 20 carbon atoms; cycloalkyl radicals having from about three to about 40 carbon atoms, preferably about three to about 30 carbon atoms; aralkyl and alkaryl radicals having from about six to about 40 carbon atoms, preferably from about six to about 30 carbon atoms; a halogen radical selected from the group consisting of fluorine, chlorine, bromine and iodine, preferably chlorine; a hydroxyl group; an alkoxy or aryloxy group; and a hydrocarbyl group, such as defined above, carrying halogen, hydroxyl or alkoxy or aryloxy; provided that at least one, preferably from about one to about four, of each of R 1  to R 8  is a sulfonato group (--SO 3   - ) or an alkyl, aryl, alkenyl, cycloalkyl, aralkyl or alkaryl group carrying a sulfonato group; M is sulfur or oxygen, preferably oxygen; E is phosphorus, arsenic, antimony or nitrogen, preferably phosphorus; and F is phosphorus, arsenic or antimony, preferably phosphorus. There is thus obtained a reaction product containing (A) a methanol phase having dissolved therein the nickel ylide catalyst and (B) an alpha olefin phase. These two phases are then separated from each other to recover the alpha olefin phase. The use of methanol as the solvent medium causes the reaction product to resolve itself into two phases, an upper phase containing most of the oligomer product and a lower methanol phase carrying the catalyst dissolved therein. This permits easy separation of the product from the reaction mixture and also permits effective recycle of methanol with dissolved catalyst. The product obtained contains normal alpha olefins having from about four to about 100 carbon atoms, generally from about four to about 50 carbon atoms.

CROSS-REFERENCES TO RELATED APPLICATIONS

Reference is made to applicants' following U.S. applications:

U.S. Patent application Ser. No. 179,079, filed Aug. 18, 1980, entitled"Nickel Ylides".

U.S. Patent application Ser. No. 179,075, filed Aug. 18, 1980, entitled"Process for the Preparation of Nickel Ylides Containing SulfonatedGroup V Ligands".

U.S. Patent application Ser. No. 179,080, filed Aug. 18, 1980, entitled"Process for the Preparation of Nickel Ylides Containing Ylide LigandsWith a Sulfonated Group V Component".

U.S. Patent application Ser. No. 179,078, filed Aug. 18, 1980, entitled"Process for the Preparation of Nickel Ylides Containing DirectlySulfonated Ylide Ligands".

U.S. Patent application Ser. No. 179,076, filed Aug. 18, 1980, entitled"Process for the Oligomerization of Ethylene".

The disclosures of the foregoing applications are hereby incorported byreference.

FIELD OF THE INVENTION

The present invention relates to the use of nickel ylides to oligomerizeethylene in methanol as the solvent medium.

DESCRIPTION OF THE PRIOR ART

It is well known in the art to use a variety of catalysts to oligomerizeethylene to higher molecular weight olefins. The term "oligomerize" hasbeen employed, and is employed herein to describe the conversion oflower olefins such as ethylene to olefinic products of higher molecularweight, e.g., to dimer, trimer, tetramer and the like. The reaction rateand product distribution obtained are highly dependent on the exactcatalyst composition and the reaction conditions employed. Two suchgeneral classes of catalysts are the "Ziegler" types consisting ofaluminum trialkyls and the "Ziegler-Natta" types consisting of aluminumalkyls or alkyl halides and titanium halides. Major disadvantages ofaluminum alkyl catalysts are their highly reactive and pyrophoric natureand the fact that they must be used at relatively high temperatures,e.g., 200°-275° C. and pressures, e.g., 2000-4000 psig (13,790 to 27,580kPa). Although much milder reaction conditions are used when thealuminum alkyls are used in conjunction with titanium halides, productquality and ease of catalyst separation from products of both of theseprior art types of catalysts are not as high as desired.

An article by W. Keim, F. H. Kowaldt, R. Goddard and C. Kruger entitled"Novel Coordination of (Benzoylmethylene)triphenylphosphorane in aNickel Oligomerization Catalyst", in Angew. Chem. Int. Ed. Engl. (1978)No. 6, page 466, discloses that a nickel ylide having the structure:##STR2## converts ethylene into alpha olefins or polyethylene.

SUMMARY OF THE INVENTION

It has now been found that ethylene can be oligomerized at relativelylow operating temperatures and pressures by reacting ethylene inmethanol under oligomerization conditions in contact with a nickel ylidedefined by the following Formula I: ##STR3## wherein R₁, R₂, R₃, R₄, R₅,R₆, R₇ and R₈ are either alike or different members selected from thegroup consisting of hydrogen, alkyl radicals having from about one toabout 24 carbon atoms, preferably from about one to about 10 carbonatoms; aryl radicals having from about six to about 20 carbon atoms,preferably from about six to about 10 carbon atoms; alkenyl radicalshaving from about two to to about 30 carbons atoms, preferably fromabout two to about 20 carbon atoms; cycloalkyl radicals having fromabout three to about 40 carbon atoms, preferably from about three toabout 30 carbon atoms; aralkyl and alkaryl radicals having from aboutsix to about 40 carbon atoms, preferably from about six to about 30carbon atoms; a halogen radical selected from the group consisting offluorine, chlorine, bromine and iodine, preferably chlorine; a hydroxylgroup; an alkoxy or aryloxy group; and a hydrocarbyl group, such asdefined above, carrying halogen, hydroxyl or alkoxy or aryloxy; providedthat at least one, preferably from about one to about four, of each ofR₁ to R₈ is a sulfonato group (--SO₃ ⁻) or an alkyl, aryl, alkenyl,cycloalkyl, aralkyl or alkaryl group carrying a sulfonato group; M issulfur or oxygen, preferably oxygen; E is phosphorus, arsenic, antimonyor nitrogen, preferably phosphorus; and F is phosphorus, arsenic orantimony, preferably phosphorus. There is thus obtained a reactionproduct containing (A) a methanol phase having dissolved therein thenickel ylide catalyst and (B) an alpha olefin phase. These two phasesare then separated from each other to recover the alpha olefin phase.

Specific examples of such nickel ylides are set forth in Table I. Inthis table and as used elsewhere herein, "Ph" represents phenyl and "Et"represents ethyl.

    TABLE I      Com-            pound R.sub.1 R.sub.2 R.sub.3 R.sub.4 R.sub.5 R.sub.6     R.sub.7 R.sub.8 E F M       1 Ph Ph Ph Ph Ph Ph SO.sub.3.sup.- Ph P P O 2 Ph Ph Ph      ##STR4##      Ph Ph H Ph P P O 3 Ph Ph      ##STR5##      Ph Ph Ph H Ph P P O 4      ##STR6##      Ph Ph Ph Ph Ph H Ph P P O 5      ##STR7##      Ph Ph Ph      ##STR8##      Ph H Ph P P O 6 Ph Ph Ph Ph Ph      ##STR9##      SO.sub.3.sup.- Ph P P O 7 Ph Ph Ph Ph Ph Ph SO.sub.3.sup.- Ph As P O 8     Ph Ph Ph Ph Ph Ph SO.sub.3.sup.- Ph P P S 9 Ph Ph Ph CH.sub.2 Ph     CH.sub.2 Ph CH.sub.2 Ph SO.sub.3.sup.- Ph P P O 10 Ph Ph Ph Ph Ph Ph     SO.sub.3.sup.- H P P O 11 Ph Ph Ph Ph Ph Ph SO.sub.3.sup.- CH.sub.3 P P     O 12 Ph Ph Ph Ph Ph Ph SO.sub.3.sup.- PhPh P P O 13 Et Et Ph      ##STR10##      Ph Ph H Ph P P O 14 Ph Ph Ph Et Et Et SO.sub.3.sup.- Ph N P O 15 Ph Ph     Ph Ph Ph Ph SO.sub.3.sup.- Ph Sb P O 16 Ph Ph Ph      ##STR11##      ##STR12##      ##STR13##      SO.sub.3.sup.- Ph P P O 17 Ph Ph Ph Ph Ph Ph (CH.sub.2).sub.3      CH.sub.2SO.sub.3.sup.- Ph P P O 18 H H H Ph Ph Ph SO.sub.3.sup.- Ph P P     O 19 Ph Ph Ph Ph      ##STR14##      Ph SO.sub.3.sup.- Ph P As O 20 Ph Ph Ph Ph Ph      ##STR15##      Ph CH.sub.3 P As S 21 Ph Ph Ph Ph Ph Ph H OCH.sub.3 P P O 22 Ph      ##STR16##     Ph Ph Ph Ph H OCH.sub.3 P P O 23 Ph Ph Ph Ph Ph Ph SO.sub.3.sup.- OEt As     P O 24 Ph CH.sub.3      ##STR17##      Ph Ph Ph H OC.sub.4 H.sub.9 P P S 25 CH.sub.3 CH.sub.3 CH.sub.3 Ph      ##STR18##      Ph SO.sub.3.sup.- OCH.sub.3 P As O 26 Ph Ph Ph Ph Ph Ph H      ##STR19##      P P O 27 Ph      ##STR20##      Ph Ph Ph Ph SO.sub.3.sup.-      ##STR21##      P P O 28 Ph Ph Ph      ##STR22##      Ph Ph H OC.sub.3      H.sub.7 As P S 29 Ph     ##STR23##      Ph Ph Ph Ph H CH.sub.3 P As O 30 Ph Ph Ph cyclo- cyclo- cyclo- SO.sub.3.     sup.- CH.sub.3 As P O     hexyl hexyl hexyl 31 CH.sub.3 CH.sub.3     CH.sub.3 Et Et Et SO.sub.3.sup.- OC.sub.4 H.sub.9 P P O 32 CH.sub.3     CH.sub.3 CH.sub.3      ##STR24##      Et Et H OC.sub.4 H.sub.9 P P O 33 Ph CH.sub.3 CH.sub.3 CH.sub.3     CH.sub.3 CH.sub.3 SO.sub.3.sup.- CH.sub.3 As As S 34 Ph      ##STR25##      Ph Ph Ph Ph H      ##STR26##      P P O 35 CH.sub.3 Et Ph      ##STR27##      Ph Ph SO.sub.3.sup.-      ##STR28##      As P S 36 H Ph Ph Ph Ph Ph SO.sub.3.sup.- H P P O 37 Ph Et Et Ph      ##STR29##      Ph SO.sub.3.sup.- CH.sub.3 As As S 38 Ph H H H H H SO.sub.3.sup.- H P P     O 39      ##STR30##      ##STR31##      ##STR32##      Ph Ph Ph H OCH.sub.3 As P O 40 Ph Ph Ph butyl butyl butyl SO.sub.3.sup.-      Ph P As O

The use of methanol as the solvent medium causes the reaction product toresolve itself into two phases, an upper phase containing most of theoligomer product and a lower methanol phase carrying the catalystdissolved therein. This permits easy separation of the product from thereaction mixture and also permits effective recycle of methanol withdissolved catalyst. The product obtained contains normal alpha olefinshaving from about four to about 100 carbon atoms, generally from aboutfour to about 50 carbon atoms.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The only components required in the reaction zone are ethylene, thenickel ylide catalyst and methanol as carrier or solvent. If desiredmethanol need not be used alone as solvent but can be used with up toabout 50 weight percent, preferably from about five to about 30 weightpercent, of the oligomer product dissolved therein. The order ofaddition of these components (ethylene, catalyst and methanol) to thereaction zone is not critical, although it is preferred that catalystand methanol first be heated to reaction temperature and then to addrapidly ethylene to the desired pressure. The reaction can be carriedout in any manner that assures contact between ethylene and catalyst,for example, in a batch reactor or in a continuous stirred tank reactor.

The amount of nickel ylide catalyst used, which is soluble in themethanol solvent, will be such that its concentration therein will be inthe range of about 0.0001 to about 1.0 moles per liter of solvent,preferably in the range of about 0.0005 to about 0.1 moles per liter ofsolvent. Ethylene is added to the reaction zone as needed, butthroughout the reaction the ethylene pressure is maintained in the rangeof about 10 to about 700 pounds per square inch gauge (68.9 to 4826kPa), preferably about 300 to about 600 pounds per square inch gauge(2069 to 4137 kPa), most preferably about 350 to about 550 pounds persquare inch gauge (2413 to 3792 kPa). The reaction temperature can be inrange of about -20° to about 200° C., preferably in the range of about20° to about 100° C. The contact time (the length of time between theexposure of catalyst to ethylene and the separation of unreactedethylene and/or reaction product from the catalyst) can be in the rangeof about one minute to about 72 hours, preferably in the range of about10 minutes to about 24 hours. Throughout the reaction period thereaction mixture is agitated. Ethylene conversion under optimum reactionconditions can be in excess of about 90 percent and can reach up toabout 99 percent.

At the end of the reaction period, the gaseous components that may bepresent in the reaction product, for example, unreacted ethylene, C₄olefins, etc., are flashed therefrom and ethylene recycled to thereaction zone if desired. The remainder of the reaction product willconsist of two liquid phases, an upper phase containing the bulk of thedesired ethylene oligomerization product and, possibly, traces ofmethanol, while the lower phase will contain methanol, catalyst and,possibly, up to about 50 weight percent, based on the total lower phase,of ethylene oligomer product, but generally from about five to about 30weight percent of ethylene oligomer product. These two phases can beseparated from each other by any conventional means, for example, bydecantation, by centrifuging, etc. In a preferred embodiment the lowermethanol phase is recycled to the reaction zone for use therein. Thecomponents of the upper liquid phase can be separated into any suitablefraction by any suitable means, for example, by fractional distillation.

The nickel ylide catalyst used in the process of this invention can beprepared using several different procedures. The following procedures,Procedure I, relates to the preparation of nickel ylides wherein thesulfonato group is located in R₄, R₅ and/or R₆ and at least one of R₄,R₅ and R₆ is aryl.

The first step in Procedure I involves sulfonating a ligand defined bythe formula: ##STR33## wherein R₄ to R₆ and E are as defined above,provided that at least one of R₄, R₅ and R₆ is an aryl group as definedabove using SO₃ in the presence of a strong inorganic mineral acid, suchas sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, etc.Specific examples of such ligands that can be used include:allyldiphenylphosphine; benzylidiphenylphosphine;bis(3-aminopropyl)phenylphosphine; bis(2-cyanoethyl)phenylphosphine;bis(m-fluorophenyl)phosphinous chloride; 4-bromophenyldiphenylphosphine;n-butyldiphenylphosphine; t-butyldiphenylphosphine;2-cyanoethyldiphenylphosphine; cyclohexyldiphenylphosphine;n-decylphenylphosphine; diallylphenylphosphine;di-n-amylphenylphosphine; di-sec-butylphenylphosphine;dicyclohexylphenylphosphine; di-ethylphenylphosphine;di-n-heptylphenylphosphine; di-n-hexylphenylphosphine;dimethylphenylphosphine; dimethyl-p-tolylphosphine;di-phenyl-n-butoxyphosphine; diphenylchlorophosphine;di-phenylenephenylphosphine; diphenylethoxyphosphine;di-phenylmethoxyphosphine; diphenylphosphine;beta-diphenylphosphinoethyltriethoxysilane;di-iso-propylphenylphosphine; di-o-tolylphenylphosphine;divinylphenylphosphine; ethyldiphenylphosphine;n-hexyldiphenylphosphine; o-methoxyphenyldiphenylphosphine;(2-methylbutyl)diphenylphosphine; methyldiphenylphosphine;methylethylphenylphosphine; methylphenylphosphine;neomenthyldiphenylphosphine; pentafluorophenyldiphenylphosphine;(2-phenylbutyl)diphenylphosphine; phenyldi-n-butoxyphosphine;phenyldichlorophosphine; phenyldiethoxyphosphine;phenyldimethoxyphosphine; phenylphosphine; isopropyldiphenylphosphine;n-propyldiphenylphosphine; o-tolyldiphenylphosphine;p-tolyldiphenylphosphine; tribenzylphosphine;tris(m-chlorophenyl)phosphine; tris(p-chlorophenyl)phosphine;tri(1-naphthyl)phosphine; triphenylphosphine;tris(4-dimethylaminophenyl)phosphine; tris(p-fluorophenyl)phosphine;tris(o-methoxyphenyl)phosphine; tris(p-methoxyphenyl)phosphine;tri-o-tolylphosphine; tri-m-tolylphosphine; tri-p-tolylphosphine;vinyldiphenylphosphine; sodium diphenylphosphinebenzene-3-sulfonate;disodium phenylphosphine-bis(benzene-3-sulfonate); dimethylphenylarsine;methyldiphenylarsine; triphenylarsine; tri-p-tolylarsine;di-phenylchloroarsine; triphenylantiomony; triphenylamine;tribenzylamine; methyldiphenylamine; and dimethylphenylamine.

It is preferred to use fuming sulfuric acid (H₂ SO₄.xSO₃, where x canbe, for example, from about 0.1 to about 0.6, preferably from about 0.2to about 0.4). The amount of SO₃ is not critical and can vary over awide range, for example, at least about one mole per mole of ligand,preferably from about two to about 20 moles per mole of ligand. The tworeactants are stirred and heated at a temperature of about 0° to about200° C., preferably about 40° to about 100° C., for about one minute toabout 48 hours, preferably for about 30 minutes to about four hours. Anysuitable pressure can be used, although atmospheric pressure ispreferred. At the end of this period the reactor contents are cooled toa temperature of about -30° to about 50° C., preferably about roomtemperature (about 26° C.), after which sufficient water and a suitablebase, such as an alkaline metal hydroxide, an alkali metal alkoxide,ammonium hydroxide, a hydrocarbyl-substituted ammonium hydroxide, etc.are added thereto to crystallize the sulfonated ligand out of solution.For example, the amount of water used can range from about 10milliliters to about 10 liters per mole of sulfonated ligand. Thecrystals can be recovered in any suitable manner, for example, byfiltration, decantation or by centrifuging.

In the second step of Procedure I, the sulfonated ligand obtained in thefirst step is reacted with any zero valent nickel compound, or anynickel compound convertible to a zero valent nickel compound in situ,and a ylide defined by the following Formula II: ##STR34## wherein R₁,R₂, R₃, R₇, R₈, M and F are as defined above. Specific examples of suchnickel compounds which can be used include:tris(triphenylphosphine)nickel; bis(cyclooctadiene)nickel;tetrakis(triphenylphosphine)nickel; bis(norbornadiene)nickel;(cycloocta-1,5-diene)duroquinone nickel; (dicyclopentadiene)duroquinonenickel; bis(tetracyclone)nickel; tetrakis(triethylphosphine)nickel;tris(triethylphosphine)nickel; bis(triphenylphosphine)nickel dicarbonyl;nickel carbonyl; nickel(II)acetylacetonate; nickelocene;bis(triethylphosphine)nickel(II)chloride;tetrakis(trifluorophosphine)nickel; nickel acetate; nickel bromide;nickel carbonate; nickel chloride; nickel fluoride; nickel iodide;nickel nitrate; nickel sulfate; nickel 2,4-pentandionate; bis π-allylnickel; and nickel di-chloride hexaamine. Specific examples of ylidescoming within the definition of Formula II are set forth in Table II.

                                      TABLE II                                    __________________________________________________________________________    Com-                                                                          pound                                                                              R.sub.1 R.sub.2 R.sub.3                                                                           R.sub.7                                                                           R.sub.8  F M                                     __________________________________________________________________________    1    Ph      Ph      Ph  H   Ph       P O                                     2    Ph      Ph      Ph  H   Ph       P S                                     3    Ph      Ph      Ph  SO.sub.3.sup.-                                                                    Ph       P O                                     4    Ph      Ph      Ph  SO.sub.3.sup.-                                                                    Ph       P S                                           ##STR35##                                                                            Ph      Ph  H   Ph       P O                                     6    Ph                                                                                     ##STR36##                                                                            Ph  SO.sub.3.sup.-                                                                    Ph       P S                                     7    Ph      Ph      Ph  H   OCH.sub.3                                                                              P O                                     8    Ph      Ph      Ph  SO.sub.3.sup.-                                                                    OCH.sub.3                                                                              R O                                     9    Ph      Ph      Ph  H   OCH.sub.3                                                                              P S                                     10                                                                                  ##STR37##                                                                            Ph      Ph  H   OCH.sub.3                                                                              P O                                     11   Ph                                                                                     ##STR38##                                                                            Ph  SO.sub.3.sup.-                                                                    OCH.sub.3                                                                              P O                                     12   Ph      Ph      Ph  H   CH.sub.3 P O                                     13   Ph      Ph      Ph  SO.sub.3.sup.-                                                                    OCH.sub.3                                                                              P O                                     14                                                                                  ##STR39##                                                                            Ph      Ph  H   CH.sub.3 P O                                     15   Ph                                                                                     ##STR40##                                                                            Ph  SO.sub.3.sup.-                                                                    CH.sub.3 P O                                     16   Ph      Ph      Ph  SO.sub.3.sup.-                                                                    CH.sub.3 P S                                     17   Ph      Ph      Ph  H   CH.sub.3 P O                                     18   CH.sub.3                                                                              CH.sub.3                                                                              CH.sub.3                                                                          H   Ph       P O                                     19   CH.sub.3                                                                              CH.sub.3                                                                              CH.sub.3                                                                          SO.sub.3.sup.-                                                                    Ph       P O                                     20   CH.sub.3                                                                              CH.sub.3                                                                              CH.sub.3                                                                          H   Ph       P S                                     21   CH.sub.3                                                                              CH.sub.3                                                                              CH.sub.3                                                                          SO.sub.3.sup.-                                                                    Ph       P S                                     22   Et      Et      Et  SO.sub.3.sup.-                                                                    Ph       P O                                     23   CH.sub.3                                                                               ##STR41##                                                                            Et  H   Ph       P O                                     24   CH.sub.3                                                                              Cyclo-  Ph  SO.sub.3.sup.-                                                                    Ph       P S                                                  hexyl                                                            25   CH.sub.3                                                                              CH.sub.3                                                                              CH.sub.3                                                                          H   OCH.sub.3                                                                              P O                                     26   CH.sub.3                                                                              Ph      Et  SO.sub.3.sup.-                                                                    CH.sub.3 P O                                     27                                                                                  ##STR42##                                                                            Ph      Et  H   OCH.sub.3                                                                              P S                                     28   CH.sub.3                                                                              CH.sub.3                                                                              CH.sub.3                                                                          H   CH.sub.3 P O                                     29   Ph      CH.sub.3                                                                              Et  SO.sub.3.sup.-                                                                    CH.sub.3 P O                                     30   Ph                                                                                     ##STR43##                                                                            CH.sub.3                                                                          H   CH.sub.3 P S                                     31   Ph      Ph      Et  SO.sub.3.sup.-                                                                    CH.sub.3 P S                                     32                                                                                  ##STR44##                                                                            CH.sub.3                                                                              Et  SO.sub.3.sup.-                                                                    CH.sub.3 P O                                     33                                                                                  ##STR45##                                                                            Ph      Ph  SO.sub.3.sup.-                                                                    Ph       P O                                     34                                                                                  ##STR46##                                                                            Ph      CH.sub.3                                                                          H   Ph       P S                                     35   CH.sub.3                                                                              CH.sub.3                                                                              Et  SO.sub.3.sup.-                                                                     ##STR47##                                                                             P O                                     36   Ph      Ph      Ph  H   Ph       As                                                                              O                                     37   Ph      Ph      Ph  H   Ph       As                                                                              S                                     38   Ph      Ph      Ph  SO.sub.3.sup.-                                                                    Ph       As                                                                              O                                     39   Ph      Ph      Ph  SO.sub.3.sup.-                                                                    CH.sub.3 As                                                                              O                                     40   CH.sub.3                                                                              CH.sub.3                                                                              CH.sub.3                                                                          H   Ph       As                                                                              O                                     41   Ph      CH.sub.3                                                                              CH.sub.3                                                                          SO.sub.3.sup.-                                                                    Ph       As                                                                              O                                     42   Ph                                                                                     ##STR48##                                                                            CH.sub.3                                                                          H   Ph       As                                                                              O                                     43   Ph      Ph      Ph  H   Ph       Sb                                                                              O                                     44   Ph      Ph      Ph  SO.sub.3.sup.-                                                                    Ph       Sb                                                                              O                                     45   Ph                                                                                     ##STR49##                                                                            Ph  H   Ph       Sb                                                                              O                                     46   Ph                                                                                     ##STR50##                                                                            Ph  SO.sub.3.sup.-                                                                    Ph       Sb                                                                              O                                     47   Ph      Ph      Ph  H   Ph       Sb                                                                              O                                     48   Ph      Ph      Ph  SO.sub.3.sup.-                                                                    Ph       Sb                                                                              S                                     49   CH.sub.3                                                                              CH.sub.3                                                                              CH.sub.3                                                                          H   Ph       Sb                                                                              O                                     50   CH.sub.3                                                                              Ph      CH.sub.3                                                                          SO.sub.3.sup.-                                                                    Ph       Sb                                                                              O                                     51   Ph      Ph      Ph  H                                                                                  ##STR51##                                                                             P O                                     52   Ph      Ph      Ph  H                                                                                  ##STR52##                                                                             P S                                     53   Ph                                                                                     ##STR53##                                                                            Ph  H   OC.sub.3 H.sub.7                                                                       P O                                     54   Ph      Ph      Ph  SO.sub.3.sup.-                                                                    OC.sub.4 H.sub.9                                                                       P O                                     55   Ph      Ph      Ph  SO.sub.3.sup.-                                                                     ##STR54##                                                                             P O                                     56   Ph      Ph      Ph  H                                                                                  ##STR55##                                                                             As                                                                              O                                     __________________________________________________________________________

In this second step approximately equal molar amounts of each of thethree reactants defined above are dissolved in any suitable unreactivesolvent, such as toluene, tetrahydrofuran, dioxane, or other unreactivehydrocarbon solvents, and stirred while maintaining a temperature ofabout 0° to about 100° C., preferably room temperature, for aboutone-half hour to about 48 hours, preferably about three to about 20hours, sufficient to ensure complete reaction. Any suitable pressure canbe used, although atmospheric pressure is preferred. The solvent can beremoved from the reaction mixture in any suitable manner, for example,by distillation, including vacuum distillation, if necessary, leavingbehind the compound defined above. On the other hand, a second solventin which the desired product is insoluble, such as heptane, can be addedto the reaction product to precipitate the compound therein. Thecompound can be recovered, for example, by filtration, decantation or bycentrifuging.

The following procedure, Procedure II, relates to the preparation ofnickel ylides wherein the sulfonato group is located in R₁, R₂, and/orR₃. In this procedure, the first step involves reacting a ligand,defined by the formula: ##STR56## wherein R₁, R₂, R₃ and F are asdefined above, provided that at least one of R₁, R₂ and R₃ is asulfonato group or an alkyl, aryl, alkenyl, cycloalkyl, aralkyl oralkaryl, as defined above, carrying a sulfonato group, with an alphasubstituted ketone or aldehyde or an alpha substituted thioketone orthioaldehyde defined by the following formula: ##STR57## wherein R₇, R₈and M are as defined above and X is a halogen radical selected from thegroup consisting of fluorine, chlorine, bromine and iodine, preferablychlorine and bromine, a tosyl group (a toluene sulfonate group), or aacetate group. The sulfonated ligand can be obtained in any conventionalmanner by sulfonating the appropriate trihydrocarbyl phosphine, arsineor stibine or by sulfonating using the procedure employed in ProcedureI. Specific examples of ligands that can be used include:allyldiphenylphosphine; benzyldiphenylphosphine;bis(3-aminopropyl)-phenylphosphine; bis(2-cyanoethyl)phenylphosphine;bis(m-fluorophenyl)phosphinous chloride; 4-bromophenyldiphenylphosphine;n-butyldiphenylphosphine; t-butyldiphenylphosphine;2-cyanoethyldiphenylphosphine; cyclohexyldiphenylphosphine;n-decylphenylphosphine; diallylphenylphosphine;di-n-amylphenylphosphine; di-sec-butylphenylphosphine;dicyclohexylphenylphosphine; di-ethylphenylphosphine;di-n-heptylphenylphosphine; di-n-hexylphenylphosphine;di-methylphenylphosphine; dimethyl-p-tolylphosphine;diphenyl-n-butoxyphosphine; diphenylchlorophosphine;diphenylenephenylphosphine; diphenylethoxyphosphine;diphenylmethoxyphosphine; diphenylphosphine;beta-diphenylphosphinoethyltriethoxysilane;di-iso-propylphenylphosphine; di-o-tolylphenylphosphine;divinylphenylphosphine; ethyldiphenylphosphine;n-hexyldiphenylphosphine; o-methoxyphenyldiphenylphosphine;(2-methylbutyl)diphenylphosphine; methyldiphenylphosphine;methylethylphenylphosphine; methylphenylphosphine;neomenthyldiphenylphosphine; pentafluorophenyldiphenylphosphine;(2-phenylbutyl)diphenylphosphine; phenyldi-n-butoxyphosphine;phenyldichlorophosphine; phenyldiethoxyphosphine;phenyldimethoxyphosphine; phenylphosphine; isopropyldiphenylphosphine;n-propyldiphenylphosphine; o-tolyldiphenylphosphine;p-tolyldiphenylphosphine; tribenzylphosphine;tris(m-chlorophenyl)phosphine; tris(p-chlorophenyl)phosphine;tri(1-naphthyl)phosphine; triphenylphosphine;tris(4-dimethylaminophenyl)phosphine; tris(p-fluorophenyl)phosphine;tris(o-methoxyphenyl)phosphine; tris(p-methoxyphenyl)phosphine;tri-o-tolylphosphine; tri-m-tolylphosphine; tri-p-tolylphosphine;vinyldiphenylphosphine; sodium diphenylphosphinebenzene-3-sulfonate;disodium phenylphosphinebis(benzene-3-sulfonate); dimethylphenylarsine;methyldiphenylarsine; triphenylarsine; tri-p-tolylarsine;diphenylchloroarsine; and triphenylantimony. Specific examples of suchalpha substituted ketones or aldehydes and of alpha substitutedthioketones or thioaldehydes that can be used herein include:phenacylchloride; phenacylbromide; alphaacetoxyacetophenone;alpha-bromo-2'-acetonaphthone; alphabromoacetone; 3-bromocamphor;alpha-bromo-p-chloroacetophenone;alpha-bromo-2',4'-dimethoxyacetophenone; alpha-bromoiosbutyrophenone;alpha-bromo-o-methoxyacetophenone; alpha-bromo-m-methoxyacetophenone;alpha-bromo-p-methoxy-acetophenone; alpha-bromo-4'-methylacetophenone;p-bromophenacrylbromide; alpha-bromopropiophenone; chloroacetone;alpha-chloro-p-fluoroacetophenone; alpha-chlorobutyrophenone;p-chlorophenacylchloride; alpha-chloropropiophenone;alpha-chlorothioacetophenone; alpha-bromothioacetophenone;alpha-chloroethylnaphthylketone; alphachloromethylacetate;alpha-bromomethylacetate; alphachloroethylacetate;alpha-bromoethylacetate; alpha-chloropropylacetate;alphachlorobutylacetate; alpha-chlorophenylacetate;alpha-chloro-p-sulfonatophenylacetate; alpha-bromopropylacetate;alpha-bromobutylacetate; alphabromophenylacetate; andalpha-bromo-p-sulfonatophenylacetate.

The reaction between the sulfonated ligand and the ketone or aldehyde iscarried out using about equal molar amounts of each reactant while theyare dissolved in an appropriate hydrocarbon solvent, such as toluene ortetrahydrofuran, and the reaction is carried out at a temperature ofabout 20° to about 200° C., preferably about 50° to about 150° C., andany suitable pressure, preferably atmospheric, for about one to about 24hours, preferably for about two to about eight hours. The reactionmixture is then cooled, preferably to room temperature. If a solidresults from such cooling it is recovered in any suitable manner, forexample, by filtration, decantation or by centrifuging. If solids do notform, the reaction mixture can be subjected to distillation to removesolvents therefrom, leaving behind solid material, which is a saltdefined by the following Formula III: ##STR58## wherein R₁, R₂, R₃, R₇,R₈, F, M and X are as defined in the previous paragraph.

To convert the above salt to the corresponding ylide, the salt isreacted with a stoichiometric amount of a base, such as an alkali metalhydroxide (sodium or potassium hydroxide), an alkyl or aryl lithium(n-butyl lithium, methyl lithium or phenyl lithium), an alkoxide (sodiummethoxide or potassium t-butoxide), a hydrocarbyl-substituted ammoniumhydroxide (benzyltrimethylammonium hydroxide), ammonium hydroxide,ammonia, etc. This can be done, for example, by suspending or dissolvingthe salt in a suitable liquid, such as water, an alcohol (ethanol orisopropanol), an aromatic (benzene or toluene), a hydrocarbon (hexane orheptane), etc. The reaction temperature can range from about roomtemperature to about 200° C., preferably from about room temperature toabout 50° C., and the reaction time from about one minute to about fourhours, or even longer, but preferably from about one to about two hours.Elevated pressures can be used, although atmospheric pressure willsuffice. If the ylide obtained is a solid, recovery can be effected byfiltration, decantation or by centrifuging. If the ylide is dissolved inthe solvent, simple distillation is sufficient to remove the solvent,leaving behind the solid ylide. In some cases in association with theylide so recovered will be the salt corresponding to the base that wasused. For example, use of sodium hydroxide produces the correspondingsodium salt. The salt and the desired ylide can be separated from eachother in any convenient manner, for example, by extraction with asolvent that will dissolve one and not the other. For example,aromatics, such as toluene, can be used to dissolve the ylide, whilewater can be used to dissolve the salt. The ylide obtained can bedefined by the following Formula IV: ##STR59## wherein R₁, R₂, R₃, R₇,R₈, F and M are as defined in Formula III.

The above identified ylide (Formula IV) is then reacted with (1) aligand defined by the formula: ##STR60## where R₄, R₅, and R₆ can be ahydrocarbyl, as defined above, a sulfonated hydrocarbyl or a sulfonatogroup, and E is as defined above; and (2) a zero valent nickel compound,following the procedure of Procedure I. Specific examples of ligandsthat can be used include: allyldiphenylphosphine;benzyldiphenylphosphine; bis(3-aminopropyl)-phenylphosphine;bis(2-cyanoethyl)phenylphosphine; bis(m-fluorophenyl)phosphinouschloride; 4-bromophenyldiphenylphosphine; n-butyldiphenylphosphine;t-butyldiphenylphosphine; 2-cyanoethyldiphenylphosphine;cyclohexyldiphenylphosphine; n-decylphenylphosphine;diallylphenylphosphine; di-n-amylphenylphosphine;di-sec-butylphenylphosphine; dicyclohexylphenylphosphine;diethylphenylphosphine; di-n-heptylphenylphosphine;di-n-hexylphenylphosphine; dimethylphenylphosphine;dimethyl-p-tolylphosphine; di-phenyl-n-butoxyphosphine;diphenylchlorophosphine; diphenylenephenylphosphine;diphenylethoxyphosphine; diphenylmethoxyphosphine; diphenylphosphine;beta-diphenylphosphinoethyltriethoxysilane;di-iso-propylphenylphosphine; di-o-tolylphenylphosphine;divinylphenylphosphine; ethyldiphenylphosphine;n-hexyldiphenylphosphine; o-methoxyphenyldiphenylphosphine;(2-methylbutyl)diphenylphosphine; methyldiphenylphosphine;methylethylphenylphosphine; methylphenylphosphine;neomenthyldiphenylphosphine; pentafluorophenyldiphenylphosphine;(2-phenylbutyl)diphenylphosphine; phenyldi-n-butoxyphosphine;phenyldichlorophosphine; phenyldiethoxyphosphine;phenyldimethoxyphosphine; phenylphosphine; isopropyldiphenylphosphine;n-propyldiphenylphosphine; o-tolyldiphenylphosphine;p-tolyldiphenylphosphine; tribenzylphosphine;tris(m-chlorophenyl)phosphine; tris(p-chlorophenyl)phosphine;tri(1-naphthyl)phosphine; triphenylphosphine;tris(4-dimethylaminophenyl)phosphine; tris(p-fluorophenyl)phosphine;tris(o-methoxyphenyl)phosphine; tris(p-methoxyphenyl)phosphine;tri-o-tolylphosphine; tri-m-tolylphosphine; tri-p-tolylphosphine;vinyldiphenylphosphine; sodium diphenylphosphinebenzene-3-sulfonate;disodium phenylphosphine bis(benzene-3-sulfonate); dimethylphenylarsine;methyldiphenylarsine; triphenylarsine; tri-p-tolylarsine;di-phenylchloroarsine; triphenylantimony; triphenylamine;tribenzylamine; methyldiphenylamine; dimethylphenylamine;bis(2-cyanoethyl)phosphine; bis(dimethylamino)methylphosphine;t-butyldichlorophosphine; 2-cyanoethylphosphine; cyclohexylphosphine;di-t-butylchlorophosphine; dicyclohexylphosphine;diethylethoxyphosphine; diethyl-iso-propoxyphosphine; diethylphosphine,triallylphosphine; tri-iso-butylphosphine; tri-n-butylphosphine;tri-sec-butylphosphine; tri-t-butylphosphine; triethylphosphine,tri-n-hexylphosphine; trimethylphosphine; trifluorophosphine;tri-iso-propylphosphine; tri-n-propylphosphine;tris(2-cyanoethyl)phosphine; tris(dimethylamino)phosphine;tris(trimethylsilyl)phosphine; tri-n-butylantimony; triethylarsine;trimethylarsine; methyldiiodoarsine; trimethylamine; triethylamine;tributylamine; tripropylamine; dimethylamine; di-n-hexylamine;dicyclohexylamine; diethylamine; tricyclohexylamine; ammonia; andphosphine.

The following procedure, Procedure III, relates to the preparation ofnickel ylides wherein the sulfonato group is in R₇. In the first step,the ylide defined by the following Formula V: ##STR61## wherein each ofR₁, R₂, R₃, and R₈ are hydrocarbyl radicals as defined above, and eachof F and M is an element as defined above, is sulfonated to obtain thefollowing sulfonated ylide defined by the following Formula VI:##STR62## wherein each of R₁, R₂, R₃, R₈, M and F is as defined inFormula V. In some cases, for example, where R₁, R₂, R₃ and R₈ arephenyl, M is oxygen and F is phosphorus the following Formula VII maymore accurately describe the structure: ##STR63##

This first step can be done, for example, by dissolving the ylide ofFormula V in a suitable solvent, for example, a halogenated hydrocarbon,such as chloroform, dichloroethane, methylene chloride or methylchloroform, or a hydrocarbon solvent, such as heptane or hexane and thenadding SO₃ to the resulting solution. The ylide and sulfonating agentare generally employed in equal molar amounts, although excesssulfonating agent can be present, if desired. Temperatures can be in therange of about 0° to about 200° C., preferably from about 20° to about100° C., pressures can be elevated, although atmospheric pressure ispreferred, and reaction times can vary from about five minutes to about24 hours, preferably from about ten minutes to about four hours.

At the end of the reaction time the compounds defined by Formula VI orVII are recovered by any suitable means. If the sulfonated desiredproduct is solid, recovery can be effected by filtration, decantation orby centrifuging. If the desired product is dissolved in the reactionmedium, recovery can be effected by distillation to remove the solventtherefrom.

The sulfonated product is converted to the corresponding ylide byreacting the same with a base, such as an alkali metal hydroxide (sodiumor potassium hydroxide), an alkyl or aryl lithium (n-butyl lithium,methyl lithium or phenyl lithium), an alkoxide (sodium methoxide orpotassium t-butoxide), a hydrocarbyl-substituted ammonium hydroxide(benzyltrimethylammonium hydroxide), ammonium hydroxide, ammonia, etc.,to produce the following ylide defined by Formula VIII: ##STR64##wherein R₁, R₂, R₃, R₈, F and M are as defined in Formula VI and A isthe cationic portion of the base used. This can be done, for example, bysuspending or dissolving the sulfonated ylide in a suitable liquid, suchas water, an alcohol (ethanol or isopropanol), an aromatic (benzene ortoluene), a hydrocarbon (hexane or heptane), etc. The reactiontemperature can range from about room temperature to about 200° C.,preferably from about room temperature to about 50° C., and the reactiontime from about one minute to about four hours, or even longer, butpreferably from about one to about two hours. Elevated pressures can beused, although atmospheric pressure will suffice. If the ylide obtainedis a solid, recovery can be effected by filtration, decantation or bycentrifuging. If the ylide is dissolved in the solvent, simpledistillation is sufficient to remove the solvent, leaving behind thesolid ylide.

The sulfonated ylide defined by Formula VIII is then reacted with (1) aligand defined by the formula: ##STR65## wherein R₄, R₅, and R₆ can behydrocarbyl, as defined above, a sulfonated hydrocarbyl or a sulfonatogroup, and E is as defined above; and (2) a zero valent nickel compound,following the procedure of Procedure I. Specific examples of ligandsthat can be used include those previously set forth in Procedure II asexamples of the ligand:

The following examples illustrate the invention, and are not intended tolimit the invention, but rather, are presented for purposes ofillustration. Examples I through III illustrate the preparation ofnickel ylides useful in the process of this invention; and Example IVillustrates the use of nickel ylides to oligomerize ethylene inaccordance with the process of this invention.

EXAMPLE I

This example is illustrative of Procedure I. To 20 milliliters of 30percent fuming sulfuric acid there were added slowly with cooling 10grams of triphenylphosphine. The solution was then heated to 80° C. andevery five minutes the solution was tested by adding one drop of thesolution to water until a clear solution was obtained. The reactionmixture was cooled to room temperature, poured into 200 cc of water andneutralized with 10 percent aqueous sodium hydroxide. After setting thesolution overnight at room temperature, the desired product separated bycrystallization and was recovered by filtration. The recovered product,sodium diphenylphosphinobenzene-3-sulfonate has the following structure:##STR67##

To 1.40 grams of bis(cyclooctadiene)nickel (5.1 millimoles) in 30milliliters of toluene under an argon atmosphere there was added asolution of 1.86 grams of Compound 1 (5.1 millimoles) and 1.94 grams(5.1 millimoles) of benzoylmethylenetriphenylphosphorane: ##STR68## in20 milliliters of toluene. After stirring for 18 hours at roomtemperature, the reaction mixture was heated to 50° C. to remove thesolvent under a reduced pressure of 10 to 100 millimeters of mercury.The reaction mixture was transferred to an argon filled dry box anddissolved in toluene. Hexane was added to precipitate the productidentified below as Compound 3. A total of 3.13 grams in 76 percentyield of the compound was recovered. ##STR69##

EXAMPLE II

This example is illustrative of Procedure II. To 4.65 grams ofalpha-chloroacetophenone (0.03 mole) in 150 milliliters of toluene therewere added 10.92 grams of Compound 1 (0.03 mole). This was heated toreflux under argon for five hours and then cooled and filtered. A totalof 14.52 grams of the phosphonium salt: ##STR70## was obtained which wassuspended in ethanol/water and titrated with 10 percent sodium hydroxideto a phenolphthalein end point. The ethanol was removed in vacuo and theproduct was washed with toluene to remove a small amount ofunsubstituted benzoylmethylene triphenylphosphorane (1.2 grams). A totalof 12.89 grams of the following phosphonium compound: ##STR71## wasobtained in 89 percent yield.

To 1.38 grams of bis(cyclooctadiene)nickel (five millimoles) in 70milliliters of tetrahydrofuran there was added a mixture of 1.31 gramsof triphenylphosphine (five millimoles) and 2.41 grams of Compound 5(five millimoles) dissolved in 70 milliliters of tetrahydrofuran. Thiswas stirred at room temperature for 18 hours, after which the solventwas removed in vacuo. The resulting product was dissolved in toluene andfiltered. Heptane was then added to precipitate the following nickelylide: ##STR72##

EXAMPLE III

This example is illustrative of Procedure III. To 4.01 grams of pyridine(0.05 mole) in 250 milliliters of dichloroethane there was added 6.97grams of sulfur trioxide (0.087 mole) of 0° C. under nitrogen. Afterstirring for 0.5 hour, a solution of 19.05 grams of unsubstitutedbenzoylmethylenetriphenylphosphorane (0.05 mole) in 200 milliliters ofdichloroethane was added. This was then heated to reflux for one hour.The reaction mixture was cooled to room temperature and the solventremoved in vacuo. The resulting product was then suspended in ethylalcohol and filtered to give 19.7 grams of a white solid of thefollowing phosphonium salt in 86 percent yield: ##STR73##

Compound 7 was also prepared as follows. To 29 grams ofbenzolylmethylenetriphenylphosphorane (0.076 mole) in 500 milliliters ofdichloroethane at 25° C. under nitrogen there was added 5.47 millilitersof sulfur trioxide (0.132 mole). After stirring for 18 hours the solventwas removed in vacuo. Then 450 milliliters of ethanol and 50 millilitersof water were added and the mixture stirred for one-half hour. Theproduct was filtered and washed with ether to give 31.8 grams, 87percent yield, of Compound 7.

Compound 7 was then suspended in water and titrated with 10 percentaqueous sodium hydroxide to a phenolphthalein end point. The water wasthen removed in vacuo and final traces removed via ethanol azeotrope togive 20.7 grams of the following ylide in 86 percent yield: ##STR74##

The nickel ylide, defined below as Compound 9, was prepared as follows.To 1.38 grams of bis(cyclooctadiene)nickel (five millimoles) in 30milliliters of tetrahydrofuran there was added a mixture of 1.31 gramsof triphenylphosphine (five millimoles) and 2.41 grams of Compound 8(five millimoles) dissolved in 70 milliliters of tetrahydrofuran. Thereaction mixture was stirred for 18 hours at room temperature, afterwhich solvent was removed in vacuo. The resulting solid was dissolved intoluene and filtered. A yellow solid, which precipitated upon additionof heptane, was recovered by filtration. A total yield of 3.65 grams ofCompound 9 was recovered in 91 percent yield. ##STR75##

When Example III above was repeated except that Compound 7 was titratedwith potassium hydroxide, ammonium hydroxide and trimethylphenylammoniumhydroxide in place of 10 percent aqueous sodium hydroxide the followingnickel ylides, respectively, were obtained: ##STR76##

In producing Compounds 10, 11 and 12 identified above, it is apparentthat the following ylides corresponding to Compound 8, respectively,will also be obtained: ##STR77##

EXAMPLE IV

Into a reactor there was charged 0.2 gram (0.25 millimole) of thespecific nickel ylide compound identified as Compound 9 in Example IIIhereof dissolved in 100 milliliters of methanol. During the reactionprecautions were taken to exclude air contamination by performing thereactions in an argon atmosphere. The reaction mixture was then heatedto 50° C. and pressured with ethylene to obtain a partial pressuretherein of 500 pounds per square inch gauge (3447 kPa). The reactionmixture was stirred during the reaction period of 18 hours, during whichperiod the pressure and temperature were maintained at the indicatedlevel. At the end of the 18-hour reaction period the reaction mixturewas cooled to room temperature and unreacted ethylene removed therefrom.Two separate and distinct phases were obtained, an upper liquid phasecontaining the desired ethylene oligomer and a lower methanol phasecontaining dissolved catalyst. The two phases were separated from eachother by decantation. Several additional runs were carried out in whichreaction temperature was varied and several wherein the reactionpressure was varied. The data obtained are tabulated below in Tables IIIand IV. In Run No. 4, 0.437 gram (0.52 millimole) of catalyst was used.

                  TABLE III                                                       ______________________________________                                                                 Activity (Moles of                                             Reaction       Ethylene Reacted                                     Run No.   Temperature, °C.                                                                      Per Mole of Catalyst                                 ______________________________________                                        1         50             22,040                                               2         40             44,989                                               3         60             10,732                                               ______________________________________                                    

                  TABLE IV                                                        ______________________________________                                                 Reaction Pressure,                                                                            Activity (Moles of                                            Pounds Per Square                                                                             Ethylene Reacted                                     Run No.  Inch Gauge (kPa)                                                                              Per Mole of Catalyst                                 ______________________________________                                        4        200 (1379)       8,728                                               5        400 (2758)      16,748                                               1        500 (3475)      22,040                                               6        600 (4137)       5,879                                               7        800 (5516)         8                                                 8        900 (6206)      Trace                                                ______________________________________                                    

The data in Table IV are unusual in that, contrary to expectations, thecatalyst activity decreased, above a certain level, as pressureincreased.

Additional runs were carried out following the procedure of Run No. 1except that (1) in place of the methanol the following solvents wereused: triethylene glycol dimethyl ether, 2-propanol, 2-ethoxyethanol,2-ethoxyethyl ether, n-butanol, (2-ethoxy)ethoxyethanol and propylenecarbonate, and (2) 0.08 gram (0.1 millimole) of the same catalyst wasdissolved in each of the solvents. Also, additional runs were carriedout following the procedure of Run No. 4 except that (1) in place of themethanol the following solvents were used: tetrahydrofuran, 50/50toluene/butanediol, toluene, acetone, anisole, ethyl acetate,acetonitrile, dioxane and ethylene glycol, and (2) 0.08 gram (0.1millimole) of the same catalyst was dissolved in each of the solvents.The uniqueness of the present process was shown by the fact that in noneof the cases wherein the above solvents were used did the reactionproduct resolve itself into two well-defined liquid phases asillustrated above wherein methanol was used as solvent.

Although the invention has been described in considerable detail withparticular reference to certain preferred embodiments thereof,variations and modifications can be effected within the spirit and scopeof the invention as described hereinbefore, and as defined in theappended claims.

We claim:
 1. A process for oligomerizing ethylene to normal alphaolefins and recovering said olefins from the reaction product whichcomprises reacting ethylene in methanol under oligomerization conditionsin contact with a nickel ylide defined by the following formula:##STR78## wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇ and R₈ are either alike ordifferent members selected from the group consisting of hydrogen, alkylradicals having from about one to about 24 carbon atoms, aryl radicalshaving from about six to about 20 carbon atoms, alkenyl radicals havingfrom about two to about 30 carbon atoms, cycloalkyl radicals having fromabout three to about 40 carbon atoms, aralkyl and alkaryl radicalshaving from about six to about 40 carbon atoms, halogen radicals,hydroxyl, alkoxy and aryloxy groups, and hydrocarbyl groups carryinghalogen, hydroxyl, alkoxy or aryloxy groups, provided that at least oneof each of R₁ to R₈ radicals is a sulfonato group or an alkyl, aryl,alkenyl, cycloalkyl, aralkyl or alkaryl carrying a sulfonato group, M issulfur or oxygen, E is phosphorus, arsenic, antimony or nitrogen and Fis phosphorus, arsenic or antimony, to obtain a reaction productcontaining (A) a methanol phase having dissolved therein said nickelylide and (B) an alpha olefin phase and then separating said phases fromeach other to recover said alpha olefin phase.
 2. A process as definedin claim 1 wherein the sulfonato group is in R₄, R₅ and/or R₆ and atleast one of R₄, R₅ and R₆ is aryl.
 3. A process as defined in claim 1wherein the sulfonato group is in R₁, R₂ and/or R₃.
 4. A process asdefined in claim 1 wherein R₇ comprises a sulfonato group.
 5. A processas defined in claim 1 wherein E and F are both phosphorus and M isoxygen.
 6. A process as defined in claim 2 wherein E and F are bothphosphorus and M is oxygen.
 7. A process as defined in claim 3 wherein Eand F are both phosphorus and M is oxygen.
 8. A process as defined inclaim 4 wherein E and F are both phosphorus and M is oxygen.
 9. Aprocess as defined in claim 6 wherein each of R₄, R₅ and R₆ is phenyl,one of which is substituted with a sulfonato group.
 10. A process asdefined in claim 9 wherein each of R₁, R₂, R₃ and R₈ is phenyl and R₇ ishydrogen.
 11. A process as defined in claim 7 wherein each of R₁, R₂ andR₃ is phenyl, one of which is substituted with a sulfonato group.
 12. Aprocess as defined in claim 11 wherein each of R₄, R₅, R₆ and R₈ isphenyl and R₇ is hydrogen.
 13. A process as defined in claim 8 whereineach of R₁, R₂, R₃, R₄, R₅, R₆ and R₈ is phenyl and R₇ is a sulfonatogroup.
 14. A process as defined in claim 13 wherein said ylide is in theform of its sodium salt.
 15. A process as defined in claim 1 whereinsaid methanol phase contains up to 50 weight percent of the oligomerproduct dissolved therein.
 16. A process as defined in claim 1 whereinsaid methanol phase contains from about five to about 30 weight percentof the oligomer product dissolved therein.
 17. A process as defined inclaim 13 wherein said methanol phase contains up to 50 weight percent ofthe oligomer product dissolved therein.
 18. A process as defined inclaim 13 wherein said methanol phase contains from about five to about30 weight percent of the oligomer product dissolved therein.
 19. Aprocess as defined in claim 14 wherein said methanol phase contains upto 50 weight percent of the oligomer product dissolved therein.
 20. Aprocess as defined in claim 14 wherein said methanol phase contains fromabout five to about 30 weight percent of the oligomer product dissolvedtherein.
 21. A process as defined in claim 1 wherein said ethylene andsaid nickel ylide are contacted at a temperature of from about -20° toabout 200° C. for about one minute to about 72 hours.
 22. A process asdefined in claim 1 wherein said ethylene and said nickel are contactedat a temperature of from about 20° to about 100° C. for about 10 minutesto about 24 hours.
 23. A process as defined in claim 13 wherein saidethylene and said nickel ylide are contacted at a temperature of fromabout -20° to about 200° C. for about one minute to about 72 hours. 24.A process as defined in claim 13 wherein said ethylene and said nickelylide are contacted at a temperature of from about 20° to about 100° C.for about 10 minutes to about 24 hours.
 25. A process as defined inclaim 14 wherein said ethylene and said nickel ylide are contacted at atemperature of from about -20° to about 200° C. for about one minute toabout 72 hours.
 26. A process as defined in claim 14 wherein saidethylene and said nickel ylide are contacted at a temperature of fromabout 20° to about 100° C. for about 10 minutes to about 24 hours.
 27. Aprocess as defined in claim 1 wherein said metal ylide is present in therange of about 0.0001 to about 1.0 moles per liter of solvent.
 28. Aprocess as defined in claim 1 wherein said metal ylide is present in therange of about 0.0005 to about 0.1 moles per liter of solvent.
 29. Aprocess as defined in claim 13 wherein said metal ylide is present inthe range of about 0.0001 to about 1.0 moles per liter of solvent.
 30. Aprocess as defined in claim 13 wherein said metal ylide is present inthe range of about 0.0005 to about 0.1 moles per liter of solvent.
 31. Aprocess as defined in claim 14 wherein said metal ylide is present inthe range of about 0.0001 to about 1.0 moles per liter of solvent.
 32. Aprocess as defined in claim 14 wherein said metal ylide is present inthe range of about 0.0005 to about 0.1 moles per liter of solvent.
 33. Aprocess as defined in claim 1 wherein the ethylene pressure ismaintained in the range of about 10 to about 700 pounds per square inchgauge (68.9 to 4826 kPa) throughout the reaction.
 34. A process asdefined in claim 1 wherein the ethylene pressure is maintained in therange of about 300 to about 600 pounds per square inch gauge (2069 to4137 kPa) throughout the reaction.
 35. A process as defined in claim 1wherein the ethylene pressure is maintained in the range of about 350 toabout 550 pounds per square inch gauge (2413 to 3792 kPa) throughout thereaction.
 36. A process as defined in claim 13 wherein the ethylenepressure is maintained in the range of about 10 to about 700 pounds persquare inch gauge (68.9 to 4826 kPa) throughout the reaction.
 37. Aprocess as defined in claim 13 wherein the ethylene pressure ismaintained in the range of about 300 to about 600 pounds per square inchgauge (2069 to 4137 kPa) throughout the reaction.
 38. A process asdefined in claim 13 wherein the ethylene pressure is maintained in therange of about 350 to about 550 pounds per square inch gauge (2413 to3792 kPa) throughout the reaction.
 39. A process as defined in claim 14wherein the ethylene pressure is maintained in the range of about 10 toabout 700 pounds per square inch gauge (68.9 to 4826 kPa) throughout thereaction.
 40. A process as defined in claim 14 wherein the ethylenepressure is maintained in the range of about 300 to about 600 pounds persquare inch gauge (2069 to 4137 kPa) throughout the reaction.
 41. Aprocess as defined in claim 14 wherein the ethylene pressure ismaintained in the range of about 350 to about 550 pounds per square inchgauge (2413 to 3792 kPa) throughout the reaction.
 42. A process asdefined in claim 1 wherein the methanol phase is recycled to thereaction zone for use therein.
 43. A process as defined in claim 13wherein the methanol phase is recycled to the reaction zone for usetherein.
 44. A process as defined in claim 14 wherein the methanol phaseis recycled to the reaction zone for use therein.